Die Stack Arrangement Comprising a Die-Attach-Film Tape and Method for Producing Same

ABSTRACT

A device includes a base substrate with a sensor component arranged thereon; a spacer layer on the base substrate, wherein the spacer layer is structured in order to predefine a cavity region, in which the sensor component is arranged in an exposed fashion on the base substrate, and a DAF tape element (DAF=Die-Attach-Film) on a stack element, wherein the DAF tape element mechanically fixedly connects the stack element to the spacer layer arranged on the base substrate and to obtain the cavity region.

This application is a divisional of U.S. patent application Ser. No.16/366,490, filed Mar. 27, 2019, which application claims the benefit ofGerman Application No. 102018204772.3, filed on Mar. 28, 2018, whichapplications are hereby incorporated herein by reference.

TECHNICAL FIELD

Exemplary embodiments relate to a device, such as a die stackarrangement, for example, comprising a sensor or MEMS component arrangedin a cavity region, and furthermore to a method for producing same.

BACKGROUND

Die stacking is a general packaging technique firstly for reducing theresulting package size and secondly for increasing the devicefunctionality. For the case where a MEMS component is intended to beaccommodated in a package, currently available stacking processes arenot directly applicable. In this case, it is usually necessary for theMEMS component to be the topmost component of the die stack. This isonly possible, however, if the MEMS component or the MEMS die is thesmallest die in the stack arrangement.

These standard packaging solutions consist, for example, in the factthat at the wafer level a closed lid element is applied on the basesubstrate over the MEMS structure to be protected, such that during thesubsequent stacking steps, i.e. when arranging further stack components,the MEMS structure is protected against so called “glue bleeding” orelse against mechanical damage. “Glue bleeding” denotes a process in thecontext of securing two components by glue, wherein during the curing ofthe glue, under the action of mechanical pressure and heat, part of theapplied glue is forced out of the mechanical contact region between thetwo components to be connected and accumulates in a manner adjoining themechanical connection region of the two components.

What is disadvantageous in conventional procedures is that specificfront end technologies, such as wafer bonding or film lamination, forexample, are required. Furthermore, as a result, relatively large stackheights also arise on account of the cover lid required. Furthermore,such front end technologies applied hitherto are relatively complex andcost intensive.

There is thus a need for a novel configuration of a die stack or a diestack arrangement, and furthermore for a method for producing acorresponding die stack.

In particular, there is a need to provide a die stack and furthermore amethod for producing a die stack in which the die stacking process canbe carried out even if the MEMS die (also called: MEMS chip) is not thesmallest die used in the stacking process.

SUMMARY

Exemplary embodiments relate in particular to a device, such as a diestack arrangement, for example, in which a stack component is arrangedon a base substrate by a DAF tape element (DAF=die attach film), whereina cavity region is maintained between the stack element and the basesubstrate in a reliable manner, wherein in the cavity region the sensorcomponent is arranged on the base substrate in an exposed fashion.

Exemplary embodiments yield a device comprising a base substrate with asensor component arranged thereon, a spacer layer on the base substrate,wherein the spacer layer is structured in order to predefine a cavityregion, in which the sensor component is arranged in an exposed fashionon the base substrate, and a DAF tape element (DAF=Die Attach Film) on astack element, wherein the DAF tape element is configured mechanicallyfixedly to connect the stack element to the spacer layer arranged on thebase substrate and to obtain the cavity region.

In accordance with one exemplary embodiment, the spacer layer, adjoiningthe cavity region, optionally comprises a bleed stopper structure havingcutouts, wherein the bleed stopper structure having the cutouts isconfigured to inhibit capillary crimping or flowing of a DAF material ofthe DAF tape element in a partly liquefied state.

In accordance with one exemplary embodiment, the bleed stopper structureis configured to exercise a capillary effect on the DAF material of theDAF tape element that is in a partly liquefied state.

In accordance with one exemplary embodiment, the bleed stopper structurearranged in the spacer layer is configured, on account of the capillaryeffect on the DAF material of the DAF tape element, to guide the partlyliquefied DAF material in a targeted manner into the cutouts and toaccommodate it there.

Exemplary embodiments furthermore yield a method for producing a stackarrangement, comprising the following steps: providing a base substratewith a sensor component arranged thereon; applying a spacer layer on thebase substrate; structuring the spacer layer in order to expose thesensor component and the associated cavity region; providing a stackelement having a DAF tape element arranged thereon and arranging thestack element having the DAF tape element on the spacer layer; andcuring the DAF tape element by exerting heat and/or mechanical pressurein order to solidify the DAF material of the DAF tape element.

In accordance with one exemplary embodiment, the step of structuring thespacer layer involves optionally forming a bleed stopper structure inthe spacer layer in a manner adjoining the cavity region, wherein thebleed stopper structure comprises cutouts. In accordance with oneexemplary embodiment, the bleed stopper structure arranged in the spacerlayer is configured, on account of the capillary effect on the DAFmaterial of the DAF tape element, to guide the partly liquefied DAFmaterial in a targeted manner into the cutouts and to accommodate itthere.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred exemplary embodiments of the present disclosure are explainedin greater detail below with reference to the accompanying drawings, inwhich:

FIG. 1A shows a schematic cross sectional view of a device or a stackarrangement in accordance with one exemplary embodiment;

FIG. 1B shows a schematic plan view of the device or stack arrangementin the plane of a spacer layer of the stack arrangement in accordancewith one exemplary embodiment;

FIGS. 2A, 2B, 2C, and 2D show schematic plan view illustrations of aplurality of different configurations of a bleed stopper structure ofthe spacer layer adjoining a cavity in accordance with one exemplaryembodiment;

FIG. 3 shows a schematic cross sectional view of a device or a stackarrangement in accordance with a further exemplary embodiment; and

FIG. 4 shows an exemplary flow diagram having the method steps of amethod for producing the device or the stack arrangement in accordancewith one exemplary embodiment.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Before exemplary embodiments of the present invention are explained morespecifically in detail below with reference to the drawings, it ispointed out that identical functionally equivalent or identically actingelements, objects, function blocks and/or method steps are provided withthe same reference signs in the various figures, such that thedescription of said elements, objects, function blocks and/or methodsteps (with identical reference signs) that is presented in variousexemplary embodiments is mutually interchangeable or can be applied toone another. In the figures, dimensions of structures, elements, layersand/or regions may be illustrated in a manner not to scale forelucidation purposes.

A basic configuration of a device 100 or a stack arrangement, e.g. inthe form of a die stack, in accordance with one exemplary embodiment,will now be described below with reference to FIGS. 1a-1b on the basisof a schematic cross sectional view and a schematic plan view.

As is illustrated in the schematic cross sectional view of the device100 illustrated in FIG. 1a , the device 100 comprises a base substrate110. The base substrate 110 can comprise for example a conductive,insulating and/or semiconducting material or else combinations thereof.In this regard, the base substrate 110 can be formed for example as adie element (semiconductor element), as a semiconductor wafer, forexample a silicon wafer, or else as a (printed) circuit board. A sensorcomponent 120 is arranged on a main surface region 110-A of the basesubstrate 110. The sensor component 120 can comprise for example a MEMScomponent, a SAW filter element or some other sensor component which isaccessible or exposed to the surrounding atmosphere at least regionally.

In the context of the present description, reference is made for exampleto so called “MEMS components” (MEMS=microelectromechanical system).MEMS components are considered to be, for example, acoustic soundtransducers, such as e.g. capacitive or piezoelectric microphones orloudspeakers, accelerometers, gyroscopes, pressure sensors for relativeor absolute pressure measurement, ultrasonic transducers, etc., in whichfor example one or more movable components mechanically coupled to abase substrate, such as membranes, for example, with electrodes for readout and/or for drive are provided, wherein the electrodes are fitted onthe membranes and/or the substrate. In the case of electrostatic MEMSpressure sensors or MEMS sound transducers, the read out is typicallyachieved by measuring the capacitance between the electrodes. In thecase of transducers acting as actuation devices (actuators), such asloudspeakers, for example, the device is driven by applying a potentialdifference via the electrodes. However, the above enumeration should notbe regarded as exhaustive, wherein the present concept is applicable toall microelectromechanical systems.

Furthermore, contact connection pads 112 can be arranged on the basesubstrate 110, e.g. on the first main surface region 110-A of the basesubstrate 110. The contact connection pads 112 (referred to as:bondpads) can be provided for electrical contacting with and connectionto the sensor component 120 via electrical conductor tracks (not shownin FIG. 1a ) arranged on or in the base substrate 110.

The device 100 furthermore comprises a spacer layer 130 on the basesubstrate 110, wherein the spacer layer 130 is structured in order topredefine a cavity region 140, wherein in the cavity region 140 thesensor component 120 is arranged on the base substrate 110 in an exposedfashion or in a manner accessible to the surrounding atmosphere. By wayof example, a pressure port (not shown in FIG. 1a ) can be provided inorder to connect the cavity 140 fluidically to the surroundingatmosphere that surrounds the device 100. The spacer layer 130 isarranged on the base substrate 110 in a mechanically fixed manner, forexample.

The device 100 furthermore comprises a DAF tape element (DAF=die attachfilm) 150 on a stack element 160, i.e. between the stack element 160 andthe spacer layer 130. The DAF tape element 150 is configured, then,mechanically fixedly to connect the stack element 160 to the spacerlayer 130 arranged on the base substrate 110 and to obtain the cavityregion 140 with the sensor component 120 arranged on the base substrate110 in an exposed fashion. The cavity region 140 is thus formed forexample between the base substrate 110 and the DAF tape element 150arranged on the stack element 160.

Contact connection pads 162 can optionally be provided on the stackelement 160 in order for example to electrically contact semiconductorcircuit elements arranged in the stack element 160 via conductor tracks(not shown in FIG. 1a ). The stack element 160 can be formed for exampleas a so called ASIC die (ASIC=Application Specific Integrated Circuit),e.g. for microphone applications. The stack element 160 can for examplefurthermore be formed merely for providing a covering functionality as ametal or glass lamina e.g. as a lid element for the cavity 140.

To summarize, with regard to the device 100 illustrated in FIG. 1a itcan thus be stated that the device 100 in the form of a stackarrangement or a die stack comprises one or more sensor components 20,e.g. MEMS components, on the base substrate 110, wherein the basesubstrate 110 can be formed for example as a semiconductor chip (die) orelse as a semiconductor wafer. The spacer layer 130, which ismechanically fixedly connected to the base substrate 110, is thenstructured in order to form the cavity region 140 with the sensorcomponent 120 arranged in an exposed fashion therein. The DAF tapeelement 150 is then arranged on the stack element 160, e.g. an ASICchip, such that the stack element 160 is mechanically fixedly connectedto the spacer layer 130 by the e.g. fully cured DAF tape element 150,wherein the cavity or the cavity region 140 is maintained around thesensor component 120.

The sensor component 120 can be referred to as exposed upwardly (i.e.vertically in the direction of the stack element 160) and laterally(i.e. laterally in the direction of the spacer layer 130) for exampleowing to the interspace formed by the cavity region 140 between thefirst main surface region 110 A of the base substrate 110 and the DAFtape element 150.

In accordance with one exemplary embodiment, the spacer layer 130,adjoining or adjacent to the cavity region 140, optionally comprises aso called “bleed stopper structure” 132 (also referred to as: glue bleedstopper structure) for the material or curable glue material of the DAFtape element 150. The optional bleed stopper structure 132, which isillustrated in a hatched manner in FIG. 1a , comprises for examplecutouts (not shown in FIG. 1a ) in the spacer layer 130, wherein thecutouts of the bleed stopper structure 132 are configured to inhibitcapillary creeping or flowing of the material of the DAF tape element150, which for example is in a partly liquefied state, i.e. the bleedstopper structure 132 is formed as “flow inhibiting” for the material ofthe DAF tape element 150. The spacer layer 130 thus comprises, forexample, a solid spacer layer region 131 and the bleed stopper structure132 adjoining the latter.

The material of the DAF tape element 150 is in a partly liquefied orviscous state e.g. before full curing. Therefore, the material of theDAF tape element 150, with mechanical pressure and/or elevatedtemperature being exerted on same, e.g. during the securing of the stackelement 160 to the spacer layer 130 or during the curing process of theDAF tape element 150, can be forced laterally out of the mechanicalcontact region 152 between the spacer layer 130 and the stack element160 and exhibit capillary creeping or flowing in the direction of thesensor component 120 in the cavity 140. With regard to specificstructural configurations of the bleed stopper structure 132, referenceis made to the exemplary embodiments in FIGS. 2a -2 d.

Reference is furthermore made hereinafter to the schematic planview—illustrated in FIG. 1b —of the device or stack arrangement 100 inthe plane AA of the spacer layer 130 parallel to the main surface region110 A of the base substrate 110 in accordance with one exemplaryembodiment.

As is illustrated in FIG. 1b , the spacer layer 130 on the basesubstrate 110 is structured so as to predefine the cavity region 140, inwhich the sensor component 120 is arranged on the base substrate 110 inan exposed fashion. Furthermore, the spacer layer 130, adjoining thecavity region 140, optionally comprises the bleed stopper structure 132having cutouts (not shown in FIG. 1b ). As is furthermore illustrated inthe schematic plan view in FIG. 1b , the spacer layer has for example anoptional pressure port 134 in order optionally to obtain a fluidconnection of the cavity region 140 to the surrounding atmosphere thatsurrounds the device 100. Consequently, pressure changes or soundpressure changes ΔP in the surrounding atmosphere can also be providedin the cavity region 140 and to the sensor element 120.

In accordance with one exemplary embodiment, the access port 140illustrated in FIG. 1b can however also be provided via the basesubstrate 110 and/or the stack element 160 having the DAF tape element150 to the cavity region 140 (not shown in FIGS. 1a-1b ). In thisregard, reference is made for example to the exemplary embodiment of thedevice 100 in FIG. 3.

The schematic illustrations illustrated in FIGS. 2a-2d in a plan view ofvarious configurations of the bleed stopper structure 132 e.g. in thespacer layer 130 will now be discussed by way of example hereinafter.What the exemplary embodiments of the bleed stopper structure 132illustrated below in FIGS. 2a-2d have in common is that the cutouts 136are arranged in the bleed stopper structure 132 in a manner adjoiningthe cavity region 140 and furthermore in a manner adjacent to oneanother around the cavity region 140 and extend e.g. parallel to themain surface region 110 A of the base substrate 110 between the DAF tapeelement 150 and the base substrate 110.

As is furthermore illustrated in FIGS. 2a-2d , the pressure port 134 canoptionally be provided in order to provide a fluid connection betweenthe cavity region 140 and the surrounding atmosphere that surrounds thedevice 100. Furthermore, it is pointed out that the bleed stopperstructure 132 can furthermore have a combination of the configurationsof the cutouts 136 illustrated below, that is to say that regionallydifferent configurations of the cutouts 136 can be provided on the bleedstopper structure 132. In this regard, by way of example, different sideregions and/or different sections of the side regions of the bleedstopper structure 132 can have different configurations of the cutouts136.

The cutouts 136 of the bleed stopper structure 132 that are formed inthe spacer layer 130 yield, with regard to the partly liquefied orviscous material to be accommodated of the DAF tape element 150, e.g.during a securing and/or curing process of the DAF tape element 150, adefined accommodating volume V₁₃₆ for the flow process of part of thepartly liquefied material of the DAF tape element 150, said flow processbeing brought about on account of the mechanical pressure and/or theelevated temperature. Each cutout 136 of the bleed stopper structure 132thus yields a defined partial volume ΔV₁₃₆, wherein with a total numberN of cutouts 136 the defined accommodating volume V₁₃₆=NΔV₁₃₆ isobtained.

The required, defined accommodating volume ΔV₁₃₆ can be determinedrelatively exactly with knowledge of the material properties of the DAFtape element 150, of the mechanical pressure exerted and of the actingtemperature, such that the capillary creeping or flowing of the partlyliquefied material beyond the bleed stopper structure 132 into thecavity region 140, which occurs during the securing or curing process ofthe DAF tape element 150, can be effectively inhibited or prevented.Substantially uncontrolled flowing or creeping of the partly liquefiedmaterial of the DAF tape element 150 can thus be effectively preventedby the bleed stopper structure 132. As a result of the specificconfiguration of the bleed stopper structure 132, the capillary forcesacting on the partly liquefied material of the DAF tape element 150 canbe set, that is to say that an energetically preferred orientation ofthe capillary forces can be obtained in order reliably to guide thepartly liquefied material of the DAF tape element 150 into the partialvolumes ΔV₁₃₆ provided by the cutouts 136 and to prevent furtherspreading in the direction of the cavity region 140.

With regard to the schematic illustrations of the cutouts 136 as shownin FIGS. 2a-2d , it is furthermore pointed out that the side surfaces ofthe cutouts 136 may be formed not exclusively rectilinearly, but also—atleast in sections—in a curved fashion, e.g. convexly or concavely, or asa polygon progression.

As is then illustrated by way of example in the schematic plan view inFIG. 2a , in accordance with one exemplary embodiment, at least oneportion of the cutouts 136 of the bleed stopper structure 132 adjoiningthe cavity region 140 has a rectangular shape.

As is shown by way of example in the schematic illustration in FIG. 2bin accordance with a further exemplary embodiment, at least one portionof the cutouts 136 of the bleed stopper structure 132, adjoining thecavity region 140, is formed in a sawtooth shaped fashion. In thisregard, at least one portion of the cutouts 136 of the bleed stopperstructure can be formed in a widening fashion proceeding from the solidsection of the spacer layer 130 in the direction of the cavity region140.

As is shown by way of example in a schematic illustration in FIG. 2c ,at least one portion of the cutouts 136 for providing the definedaccommodating volume V₁₃₆ can be formed in a tapering fashion proceedingfrom the solid region of the spacer layer 130 in the direction of thecavity region 140.

As is shown by way of example in the schematic illustration in FIG. 2d ,the bleed stopper structure 132 comprises a columnar structure having amultiplicity of spaced apart columns 138 formed e.g. perpendicular tothe main surface region 110-A of the base substrate 110 with the cutouts136 formed between the adjacent columns 138. The spacing and thediameter of the columns can be varied for example between inner andouter rows of columns with respect to the cavity region 140 in order toset the capillary effects acting on the partly liquefied material of theDAF tape element 150 during a partly liquefied state thereof such thatthe partly liquefied material of the DAF tape element 150 spreads withinthe cutouts 136 defined by the columns.

In accordance with one exemplary embodiment, at least one portion of thecutouts 136 for providing the defined accommodating volume V₁₃₆ can beformed in a trench shaped fashion or have a trench structure proceedingfrom the solid region of the spacer layer 130 in the direction of thecavity region 140.

With regard to the above exemplary embodiments of the bleed stopperstructure 132 with reference to FIGS. 2a-2d , it is pointed out thatthis enumeration should be regarded only as by way of example, but notas exhaustive, wherein the present concept can be applied to furtherconfigurations of the bleed stopper structure 132, provided that thebleed stopper structure 132 firstly predefines a defined accommodatingvolume V₁₃₆ for the material of the DAF tape element 150 in a partlyliquefied or viscous state thereof, e.g. during a securing and/or curingprocess, and furthermore provides for guiding the partly liquefiedmaterial of the DAF tape element 150 in a targeted manner by a targetedorientation of the capillary forces on the partly liquefied or viscousmaterial of the DAF tape element 150.

In accordance with one exemplary embodiment, the cavity region 140 canbe formed at least partly in a rectangular fashion parallel to the mainsurface region 110-A of the base substrate 110, wherein the cutouts 136which are formed in the bleed stopper structure 132 of the spacer layer130 and which adjoin corner regions of the rectangular cavity region 140are dimensioned to be larger, for example at least by a factor of 1.5,or 2 than the remaining cutouts 136 adjoining the side regions, i.e.longitudinal and transverse sides, of the rectangular cavity region 140.

In accordance with one exemplary embodiment, the cutouts 136 formed inthe bleed stopper structure 132 of the spacer layer 130 are arrangedsymmetrically around the cavity region 140 with the MEMS component 120situated therein.

In accordance with one exemplary embodiment, the spacer layer can havefor example a thickness in a range of between 5 and 50 μm or in a rangeof between 10 and 20 μm. In accordance with one exemplary embodiment,the DAF tape element 150 e.g. in a substantially undeformed state of thelayer 150 can have a thickness d130 in a range of 5 to 50 μm or in arange of 12 to 20 μm. The DAF tape element can comprise a for exampleso-called “bi stage material” (also called b stage material), such ase.g. a partly crosslinked epoxy material layer (=a layer composed of apartly crosslinked epoxy material), and can be structured like a film.

A b stage material layer 150 cured in a medium stage is considered tobe, for example, a layered b stage epoxy material which is cured (partlypolymerized or partly crosslinked) to a medium stage and is stillplastically deformable or flexible, but is dimensionally stable enoughto form the cavity 140 above the sensor component 120.

A b stage material can comprise for example a medium curing stage(softbake=partly crosslinked or partly polymerized) and a fully curedstage (hardbake=fully crosslinked or fully polymerized), which can beachieved in a targeted manner by corresponding curing processes.

The spacer layer 130 can comprise for example a plastics material fromthe imide group, i.e. polyimide. Furthermore, the material of the spacerlayer 130 can comprise a material comprising epoxy resin, such as e.g.an SU8 material (photoresist).

In accordance with exemplary embodiments, therefore, the spacer layer130, adjoining the cavity region 140, is provided with a bleed stopperstructure 132 for the glue material of the DAF tape element 150 with thecutouts 136, wherein the bleed stopper structure 132 or thecorrespondingly formed cutouts 136 are configured to inhibit capillarycreeping or flowing of the material of the DAF tape element 150 e.g. ina partly liquefied state thereof during the securing and/or curingprocess, e.g. under the action of mechanical pressure and elevatedtemperature. The bleed stopper structure 132 thus constitutes a flowinhibiting property for the partly liquefied material of the DAF tapeelement.

In accordance with one exemplary embodiment, the bleed stopper structure132 or the corresponding cutouts 136 are configured to exercise acapillary effect on the material of the DAF tape element 150 that is ina partly liquefied state, said capillary effect being in-creased bycomparison with that in the cavity region 140. Consequently, the bleedstopper structure 132 arranged in the spacer layer 130 is configured, onaccount of the (increased) capillary effect thereof on the material ofthe DAF tape element 150 if the latter is in a partly liquefied state,to guide it into the cutouts 136 in a targeted manner and to accommodateit there.

In accordance with one exemplary embodiment, the bleed stopper structure132 is configured to accommodate the partly liquefied material of theDAF tape element during a curing process and to inhibit the capillarycreeping or flowing process of the partly liquefied material of the DAFtape element 150.

In accordance with one exemplary embodiment, the bleed stopper structureis thus formed in the spacer layer laterally, i.e. parallel to the mainsurface region 110 A of the base substrate 110, between the cavityregion 140 and a solid material region (also called: remaining region)of the spacer layer 130, wherein the spacer layer 130 extends e.g.parallel to the main surface region 110 A of the base substrate 110and/or a main surface region 160 A of the stack element 160.

In accordance with one exemplary embodiment, the cutouts 136 formed inthe spacer layer 130 through the bleed stopper structure 132 yield, withregard to the partly liquefied material to be accommodated of the DAFtape element 150, a defined or predefined accommodating volume V₁₃₆ forthe partly liquefied material of the DAF tape element 150.

A schematic cross sectional view of a stack arrangement 100 inaccordance with a further exemplary embodiment will now be describedbelow with reference to FIG. 3.

The exemplary embodiments illustrated with regard to FIGS. 1a-2b and2a-2d above are substantially equally applicable to the stackarrangement illustrated in FIG. 3, i.e. in particular the explanationsregarding the spacer layer 130 with the optional bleed stopper structure132.

As is illustrated in FIG. 3, a cutout or base substrate cavity 114 isprovided in the base substrate 110 proceeding from the second mainsurface region 110 B thereof and extends as far as a base substratepartial section 116 on which the sensor component 120 is arranged. Thebase substrate partial section 116 is mechanically connected or coupledto the remaining region 118 of the base substrate 110 for example by socalled “spring elements” or “stress decoupling elements” 117. Since thisconfiguration makes it possible to provide an access port proceedingfrom the second surface region 110 B of the base substrate 110 to thecavity region 140, via which port the cavity region 140 is fluidconnected to the surrounding atmosphere of the device 100, for example,the access port 134 from FIG. 1b can optionally be omitted, for example,such that the spacer layer 130 and the bleed stopper structure 132 canbe formed as completely surrounding the cavity region 140.

In the case of the device 100 in FIG. 3, therefore, the sensor component120 is arranged on the base substrate partial section 116, which is inturn mechanically connected or coupled to the remaining region 118 ofthe base substrate 110 by the spring elements 117. The spring elements117 can be provided for the stress decoupling of the material, e.g. thesemiconductor material, of the base substrate partial section 116 fromthe remaining region 118 of the base substrate 110.

Otherwise, the above explanations concerning the exemplary embodimentsof the device 100 as discussed with reference to FIGS. 1a-1b and 2a-2bare equally applicable to the device 100 in FIG. 3.

Specific configurations and the resultant technical effects of variouselements of the present device or stack arrangement 100 will bediscussed in summary once again hereinafter.

The present concept combines the functionality of DAF tapes or DAF tapeelements 150 and a specifically configured spacer layer 130 having theglue bleed stopper structure 132, which can be formed for example froman SU8 material or some other epoxy resin material or plastics material(e.g. polyimide). The DAF tape element is substantially non liquid andbecomes “creeping” or “flowing” only at the regions with high exertedmechanical force along the cavity edges. However, it is precisely at thecavity edges, i.e. the marginal region of the cavity region 140, thatthe bleed stopper structure is formed e.g. as an integrated section ofthe spacer layer 130 as an array of cutouts 136 extending around thecavity region 140, which cutouts will accommodate the bleeding materialfrom the DAF tape element 150, for example during the securing or curingprocess thereof by elevated mechanical pressure and/or elevatedtemperature. Finally, the cavity region 140 can be formed by the topmoststack element 160, which can be formed for ex-ample as an ASIC die/chip(e.g. a microphone ASIC) or else as a metal or glass laminar, with thespacer layer 130 arranged thereon.

In accordance with exemplary embodiments, the spacer layer 130 can thencomprise, in the region adjoining the cavity or the cavity region 140,the so called “bleed stopper structure” 132 for suppressing capillarycreeping or flowing of the partly liquefied DAF material 150 during theprocess of attaching the stack element 160 provided with the DAF tapeelement 150 to the spacer layer 130 or during the curing of the materialof the DAF tape element 150. The bleed stopper structure 132 can havevarious geometric shapes, for example, such as e.g. columnsperpendicular to the die plane, i.e. perpendicular to the main surfaceregion 110 A of the base substrate 110, widening and/or tapering in thedirection of the cavity region 140 with the MEMS component 120, e.g. inthe form of a sawtooth pattern parallel to the die plane or elserectangular parallel to the die plane.

The function of the bleed stopper structure 132 comprises, then, inpreventing or controlling capillary creeping or flowing of the DAFmaterial in the direction of the MEMS component 120 in the cavity 140during the process of joining together the stack elements or during thecuring of the DAF layer element and the partial liquefaction of thematerial of the DAF tape element that inevitably occurs there. For thispurpose, in the transition region between the solid spacer layer and thecavity 140 (with the sensor component 120), the bleed stopper structure132 comprises a column structure, sawtooth structure, trapezoidalstructure, rectangular structure, etc., which at least inhibits orprevents uncontrolled flowing of the partly liquefied DAF material onaccount of the capillary forces (brought about as a result of thespecific configuration of the bleed stopper structure).

The bleed stopper structure 132 thus yields firstly, for the partlyliquefied DAF material, a flow movement inhibiting region on account ofincreased capillary forces on the partly liquefied DAF material, andsecondly a volume which is set in a targeted manner and is enlargedsufficiently to accommodate the partly liquefied DAF material flowing orcreeping in capillary fashion under elevated temperature and/or elevatedmechanical pressure influence and to stop the movement of said materialin the direction of the cavity region 140 in a defined manner, such thatsubstantially defined cavity dimensions can be achieved above andlaterally with respect to the sensor component 120 during productioneven as a mass produced product, e.g. at the wafer level.

Furthermore, the bleed stopper structure 132 provided makes it possibleto obtain the function of mechanical intermeshing of the DAF materialwith the spacer layer 130, as a result of which an increase in themechanical strength of the stack arrangement 100 with the sensorcomponent 120 can be obtained. The structured region of the bleedstopper structure of the spacer layer 130 can thus obtain a connectionover the largest possible area via the DAF material of the DAF tapeelement between the stack element 160 and the spacer layer 130 arrangedon the base substrate 110 in order to achieve a large bonding area or alarge mechanical contact area and thus an increased mechanical stabilitybetween the layers of the stack arrangement 100.

In the case of the bleed stopper structure 132, at the corners of thecavity region 140 by enlarged cutouts 136 more space or room can be keptavailable in order to be able to accommodate the partly liquefied DAFmaterial that is usually forced in there to an increased extent.Furthermore, the bleed stopper structure 132 is arranged for examplesymmetrically around the cavity region 140 and thus around the sensorcomponent 120. Consequently, the bleed stopper structure 132 yields adefined stop region for the partly liquefied DAF material and thusprovides defined lateral and also vertical dimensions for the cavityregion 140.

The device or stack arrangement 100 as described above makes it possibleto achieve a reduced overall height of the package or stack.Furthermore, very low defined cavity heights of less than 10 μm are ableto be realized. Furthermore, it is possible that the packaging or stackarrangement process can be carried out directly after the front end ofline process (FEOL process), e.g. at the wafer level.

An exemplary flow diagram of a method for producing the device or stackarrangement 100 in accordance with one exemplary embodiment will now bedescribed below with reference to FIG. 4.

In the method 200 for producing a stack arrangement 100, firstly a step210 involves providing a base substrate 110 with a sensor component 120arranged thereon.

A step 220 involves forming or applying a spacer layer 130 on the basesubstrate 110. This can be carried out by a deposition process, forexample.

A step 230 involves structuring the spacer layer 130 in order to exposethe sensor component 120 and the associated cavity region 140.Structuring 230 the spacer layer 130 can be carried out byphotolithographically exposing the sensor or MEMS component 120 and theassociated cavity region 140, wherein optionally it is furthermorepossible to form a bleed stopper structure 132 in a manner adjoining thecavity region 140 in the spacer layer 130.

A step 240 involves providing a stack element 160 with a DAF tapeelement 150 arranged thereon, wherein a step 250 involves arranging ormechanically fixing the stack element 160 with the DAF tape element 150arranged thereon on the spacer layer 130. Mechanically fixing the stackelement 160 with the DAF tape element 150 arranged thereon on the spacerlayer 130 can for example already be carried out by exerting mechanicalpressure and bring about capillary creeping or flowing of the partlyliquefied DAF material of the DAF tape element 150.

In a step 260, the DAF tape element 150 can be cured by exerting heatand/or mechanical pressure in order to solidify the DAF material of theDAF tape element 150.

In accordance with one exemplary embodiment, in the step of structuring230 the spacer layer 130, it is possible to form the optional bleedstopper structure 132 in the spacer layer 130 in a manner adjoining thecavity region 140, wherein the bleed stopper structure 132 comprisescutouts 136. The bleed stopper structure 132 can be provided for exampleby an etching process at the region between the cavity region 140 andthe continuous or solid spacer layer 130.

The base substrate 110 can be formed for example as a die element(semiconductor element), as a semiconductor wafer, for example a siliconwafer, or else as a (printed) circuit board. If the base substrate 110is formed as a semiconductor wafer, e.g. a silicon wafer, as a furtheroptional step the base substrate 110 with the elements arranged thereoncan also be singulated in order to provide singulated components.

In accordance with one exemplary embodiment, the cutouts 136 arranged inthe bleed stopper structure 132 can be configured, during step 150 ofarranging or during step 160 of curing the DAF tape element 150, onaccount of providing capillary forces on the partly liquefied DAFmaterial of the DAF tape element 150, to guide the partly liquefied DAFmaterial in a targeted manner into the cutouts 136 and to accommodate itthere.

In accordance with one exemplary embodiment, the bleed stopper structure132 arranged in the spacer layer 130 can be configured, on account ofthe capillary effect on the partly liquefied DAF material of the DAFtape element 150, at least to inhibit capillary creeping or flowing ofthe partly liquefied DAF material of the DAF tape element 150 into thecavity region 140.

Although some aspects of the present disclosure have been described asfeatures in the context of a device, it is clear that such a descriptioncan likewise be regarded as a description of corresponding methodfeatures. Although some aspects have been described as features inassociation with a method, it is clear that such a description can alsobe regarded as a description of corresponding features of a device or ofthe functionality of a device.

In the detailed description above, in some instances different featureshave been grouped together in examples in order to rationalize thedisclosure. This type of disclosure ought not to be interpreted as theintention that the claimed examples have more features than areexpressly indicated in each claim. Rather, as represented by thefollowing claims, the subject matter can reside in fewer than allfeatures of an individual example disclosed. Consequently, the claimsthat follow are hereby incorporated in the detailed description, whereineach claim can be representative of a dedicated separate example. Whileeach claim can be representative of a dedicated separate example, itshould be noted that although dependent claims refer back in the claimsto a specific combination with one or more other claims, other examplesalso comprise a combination of dependent claims with the subject matterof any other dependent claim or a combination of each feature with otherdependent or independent claims. Such combinations shall be encompassed,unless an explanation is given that a specific combination is notintended. Furthermore, the intention is for a combination of features ofa claim with any other independent claim also to be encompassed, even ifthis claim is not directly dependent on the independent claim.

Although specific exemplary embodiments have been illustrated anddescribed herein, it will be apparent to a person skilled in the artthat a multiplicity of alternative and/or equivalent implementations canbe substituted for the specific exemplary embodiments shown andillustrated there, without departing from the subject matter of thepresent application. This application text is intended to cover alladaptations and variations of the specific exemplary embodimentsdiscussed and described herein. Therefore, the present subject matter ofthe application is limited only by the wording of the claims and theequivalent embodiments thereof.

What is claimed is:
 1. A method for producing a stack arrangement,comprising the following steps: providing a base substrate with a sensorcomponent arranged thereon; applying a spacer layer on the basesubstrate; structuring the spacer layer in order to expose the sensorcomponent and an associated cavity region; providing a stack elementhaving a DAF (Die Attach Film) tape element arranged thereon andarranging the stack element having the DAF tape element on the spacerlayer; and curing the DAF tape element by exerting heat and/ormechanical pressure in order to solidify DAF material of the DAF tapeelement.
 2. The method as claimed in claim 1, wherein structuring thespacer layer comprises forming a bleed stopper structure in the spacerlayer in a manner adjoining the cavity region, and wherein the bleedstopper structure comprises cutouts.
 3. The method as claimed in claim2, wherein the cutouts arranged in the bleed stopper structure areconfigured, during the step of curing the DAF tape element, due toproviding capillary forces on partly liquefied DAF material of the DAFtape element, to guide the partly liquefied DAF material in a targetedmanner into the cutouts and to accommodate it there.
 4. The method asclaimed in claim 2, wherein the cutouts comprise a rectangular shape. 5.The method as claimed in claim 2, wherein the cutouts comprise asawtooth shape.
 6. The method as claimed in claim 2, wherein the cutoutscomprise a tapering shape.
 7. The method as claimed in claim 2, whereinthe cutouts comprise a curved shape.
 8. The method as claimed in claim2, wherein the cutouts comprise a combination of at least twodifferently-shaped types of cutouts.
 9. The method as claimed in claim2, wherein the base substrate comprises a base substrate cavity.
 10. Themethod as claimed in claim 2, wherein the spacer layer comprises apressure port to obtain a fluid connection of the cavity region to asurrounding atmosphere that surrounds the stack arrangement.
 11. Amethod for producing a stack arrangement, comprising: providing a basesubstrate with a sensor component arranged thereon; applying a spacerlayer on the base substrate; structuring the spacer layer in order toexpose the sensor component and an associated cavity region; providing astack element having a DAF (Die Attach Film) tape element arrangedthereon and arranging the stack element having the DAF tape element onthe spacer layer; and forming a bleed stopper structure in the spacerlayer in a manner adjoining the cavity region, wherein the bleed stopperstructure comprises cutouts, and wherein the cutouts arranged in thebleed stopper structure are configured, during curing the DAF tapeelement, to guide partly liquefied DAF material into the cutouts and toaccommodate it there.
 12. The method of claim 11, wherein curing the DAFtape element comprises exerting heat and/or mechanical pressure in orderto solidify DAF material of the DAF tape element.
 13. The method ofclaim 11, wherein the cutouts comprise a rectangular shape.
 14. Themethod of claim 11, wherein the cutouts comprise a sawtooth or taperingshape.
 15. The method as claimed in claim 2, wherein the cutoutscomprise a curved shape.
 16. A method for producing a stack arrangement,comprising: providing a spacer layer in the stack arrangement comprisinga component and an associated cavity region; providing a stack elementhaving a DAF (Die Attach Film) tape element arranged thereon andarranging the stack element having the DAF tape element on the spacerlayer; and forming a bleed stopper structure in the spacer layer in amanner adjoining the cavity region, wherein the bleed stopper structurecomprises cutouts, and wherein the cutouts arranged in the bleed stopperstructure are configured, during curing the DAF tape element, to guidepartly liquefied DAF material into the cutouts and to accommodate itthere.
 17. The method of claim 16, wherein curing the DAF tape elementcomprises exerting heat and/or mechanical pressure in order to solidifyDAF material of the DAF tape element.
 18. The method of claim 16,wherein the cutouts comprise a rectangular or triangle shape.
 19. Themethod of claim 16, wherein the cutouts comprise a curved shape.
 20. Themethod of claim 16, wherein the cutouts are formed by a columnarstructure in the bleed stopper structure having a multiplicity of spacedapart columns.